1. Field of the Invention
This invention relates to stress activated high load additives and to lubricant compositions containing such additives. The load additives are activated under high load conditions such as engine operating conditions.
2. Description of the Related Art
Lubricants typically require the presence of additives to protect moving parts from the adverse effects of friction. Load-carrying additives are commonly added to oils and greases to improve the ability of the oil or grease under friction producing stress to protect from wear and damage to moving metal parts. For example, U.S. Pat. Nos. 4,144,180; 4,456,539 and 4,626,368 disclose triazole derivatives having a phosphorous moiety directly bound to the triazole ring system. These additives show load-carrying, antioxidant or antiwear properties and are active without regard to operating conditions.
Some of the problems presented by many typical additives relate to seal degradation and lubricant incompatibility. It would be desirable to have a high load lubricant additive which becomes activated only under the stress of operating conditions thereby avoiding prolonged contact of active species with seals and other sensitive components.